# Mandrel sources?

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-Brian Barney
TRA #8896 L2

#### Stymye

##### Well-Known Member
Brian,thanks for posting it

#### GL-P

##### Well-Known Member
nice, thanks for posting it

I'm gonna be doing some CF tubes also in the 24mm range. Our 29mm mandrel will be a max. of 21 inches long to reduce vibrations. The 24mm mandrel will be some turned down Delrin cuz it is pretty slippery even without mold release. (Just don't wan't to mess up a mandrel!)

#### edwardw

##### Well-Known Member
Where was your tool when you were turning down the tube? Above, below or at center?

Also, 2" Schedule 80 T-6061 Aluminum Tube can be turned down to make 54mm motors.

Edward

#### Brian Barney

##### Well-Known Member
I had the cutting tool on the centerline of the project.. my machining teacher helped me with the setup. whats the method of finding the maximum length? I have only heard the unsupported length should be no more than 3 times the diameter of the rod.
Thanks for the input.

-Brian Barney

#### edwardw

##### Well-Known Member
When I run turning operations typically I go between .002 and .005 above center. This is because sometimes the tool can deflect downward under the stress and then the work tries to jump and it chatters. Next time maybe try setting it a little high on a scrap piece and trying it out.

Edward

#### Micromeister

##### Micro Craftman/ClusterNut
TRF Supporter
Brian:
if you can't get the Alum tube to turn try 2.25" Delrin (Black) #8576K31 about 20.79per foot.
Turns really well with standard tools. Available in 1foot sections from McMaster-Carr. Wonderful for laying up FAI type model bodies and nosecones. No release agent required just throw the harded glassed combo in the freezer for a few minutes, body pop's right off

#### GL-P

##### Well-Known Member
if you can't get the Alum tube to turn try 2.25" Delrin (Black) #8576K31 about 20.79per foot.Turns really well with standard tools. Available in 1foot sections from McMaster-Carr. Wonderful for laying up FAI type model bodies and nosecones. No release agent required just throw the harded glassed combo in the freezer for a few minutes, body pop's right off
Seriously? We found some Delrin locally. I'll be making some 24mm*2ft sections.

Time for experimentation!!!